The present invention is related to the procedure and apparatus for protecting vehicles against reconnaissance by IR-imaging equipment, preferably in the spectral region of self-radiation of the vehicles by the addition of cooling air. The hot or warm exhaust gases are surrounded by a laminar flow of cold air as the inventors have previously proposed in German Patent application P27 31 205.6, U.S. Ser. No. 916,959 on June 19, 1978, now abandoned.
The object of the present invention is to appreciably reduce the very strong thermal signatures of battle tanks and trucks, to avoid the reconnaissance and detection at larger distances. For example, the battle tanks of today can be recognized at distances larger than 5 km, particularly when they are moving and can be identified by their characteristic movements of the hot spots.
The thermal signatures or identifying characteristics are caused on the one hand by the outside parts of the tank body heated-up by the motor or the tank's cooling system and on the other hand by the discharge locations of the hot exhaust gases, which are blown off at different places depending on the type of vehicle. The present designs of military vehicles did not take into account these signatures since the tank or vehicle designers had no information on the threat of detection from IR reconnaissance systems and IR trackers.
The object of the present invention is, therefore, to provide procedures and apparatus assemblies which largely avoid the detection of the exhaust openings as well as the heating-up of the outer shell of the vehicle by means of IR reconnaissance systems.
Another object of the present invention is to provide an arrangement, of the foregoing character, which is substantially simple in construction and may be economically fabricated.
A further object of the present invention is to provide an arrangement, as described, which does not require specially-skilled operating personnel to apply.